I would like to realize a simple fade-out to black or white (without changing to a black or white room) via lua, for example to display texts, while the shaded room stays in the background.
It seems to be a lot of effort to do that without lua: For each room i would have to create a huge black picture in full hd resolution (or use a smaller one while scaling it up to full hd via lua). This is not just a lot of effort, but also not very space saving.
So... what about the chances to create a general function that uses 1 (!) pretty small PNG to be scaled up to the game resolution. This script could be used for each room that might need it.
A must is, that opacity and fade-speed could be controlled in a variable.